A novel sensor-less induction motor based on fuzzy sliding-mode control

A novel fuzzy sliding-mode structure have been proposed for the model reference adaptive system(MRAS) based sensor-less control of an induction motor in this paper. The design includes a hybrid MRAS from measured stator terminal voltages and currents. The estimated speed is used as feedback in an indirect vector control system achieving the speed control without the use of shaft mounted transducers. Fuzzy Sliding-Mode Structure include two nonlinear controllers, one of sliding mode type and the other PI-fuzzy logic based, define a new control structure. Both controllers are combined by means of an expert system based on Takagi-Sugeno fuzzy reasoning. The sliding mode controller acts in the steady state. The new structure embodies the advantages that both nonlinear controllers offer sliding mode controllers increasing system stability limits and PI-like fuzzy logic based controllers reducing the chattering in permanent state. The scheme has been implemented and experimentally validated.